East pediment Pausanias 5.10.8 ff.:
To come to the pediments: in the front pediment there is, not yet begun, the chariot-race between Pelops and Oenomaus, and preparation for the actual race is being made by both. An image of Zeus has been carved in about the middle of the pediment; on the right of Zeus is Oenomaus with a helmet on his head, and by him Sterope his wife, who was one of the daughters of Atlas. Myrtilus too, the charioteer of Oenomaus, sits in front of the horses, which are four in number. After him are two men. They have no names, but they too must be under orders from Oenomaus to attend to the horses.At the very edge lies Cladeus, the river which, in other ways also, the Eleans honor most after the Alpheius. On the left from Zeus are Pelops, Hippodameia, the charioteer of Pelops, horses, and two men, who are apparently grooms of Pelops. Then the pediment narrows again, and in this part of it is represented the Alpheius. The name of the charioteer of Pelops is, according to the account of the Troezenians, Sphaerus, but the guide at Olympia called him Cillas. The sculptures in the front pediment are by Paeonius, who came from Mende in Thrace.